Method and machine for jointing bands in motion



Dec. 22, 1970 F. OSTA 3,549,458

METHOD AND MACHINE FOR JOAINTING BANDS IN MOTION- Filed Sept. 20, 1966 4 Sheets-Sheet 1 INVENTOR BY f y i ATTORNEYS Dec. 22, 1970 F. OSTA 3,549,458-

METHOD AND MACHINE FOR JOINTING BANDS IN MOTION Filed Sept. 20. 1966 4 Sheets-Sheet .i

I N VE NT( )R F94 NCESCO 0: n4

BY v Jim/4n,

ATTORNEYS Dec. 22, 1970 os A 3,549,458

METHOD AND MACHINE FOR JOINTING BANDS IN MOTION Filed Sept. 20, 1966 4 Sheets-Sheet 3 36 9 3 4D 35 26 22 10 1 3? "T 32 23 [a i 2 If. J? s FIG. 5

INVENTOR EMA 05500 Os r4 ATTORNEYS METHOD AND MACHINE FOR JOINTING BANDS-IN MOTION Filed Sept. 20, 1966 F. OSTA Dec. 22; 1970 4 Sheets-Sheet 4.

FIG.8I

INVENTOR ATTORNEYS Patented Dec. 22, 1970 METHOD AND MACHINE FOR JOINTING BANDS IN MOTION Francesco Osta, Piedmont, Italy (Rotomec, Casella Postale 2 Casale Monferrato (Alessandria), Italy) Filed Sept. 20, 1966, Ser. No. 580,626

Claims priority, application Italy, Sept. 30, 1965,

21,986/ 65 Int. Cl. B31f 5/00 US. Cl. 156-505 8 Claims ABSTRACT OF THE DISCLOSURE A depleted web from an old roll is replaced by a web from a new roll, with the formation of a taped butt joint, by bringing the new roll up to speed, pressing the old web against the new roll and picking the free end of the new web adhesively off the new roll thereby forming a temporary superposed joint, cutting through this temporary joint, deflecting the head end of the new web and the tail end of the old web from the feed path, and taping the new butt joint which thus formed between the old and new webs.

'tuted for the first. Since an interruption in the feed would cause serious inconveniences, it is necessary to provide a jointing between the end portion of the nearly depleted band and the initial portion of the new band, so that continuity of the running band is ensured. Furthermore, from the industrial point of view it is very opportune that this jointing should take place without stopping the rotary machine, indeed the operation should not even involve a slowing down of the motion of the rotary machine.

When the band material has a very reduced thickness (e.g. in the case of paper), the jointing in question is made by superposition of part of the two bands, and the problem of performing the jointing by superposition with the machine in operation and without a slowing-down of same may be regarded as already satisfactorily solved by the existing techniques. On the contrary, when the thickness of the material is relatively considerable (for instance, in the case of cardboard) a jointing by snper position with consequent double thickness of a hand area would give rise to inconveniences and cannot, therefore, be accepted. In such cases an end to end jointing is resorted to, i.e., the end portion of the old band and the initial portion of the new one are correspondingly cut and juxtaposed, whereafter the continuity is ensured by applying two joint covering strips of adhesive tape. Using the means offered by present day techniques, this comparatively complex operation cannot be carried out with the band running at a high speed. The known systems pro: vide a pair of rollers fitted with exactly corresponding knives, and a pair of strip applying rollers: the end of the new band is manually introduced between said rollers at a standstill, between which the nearly wound off band is running. Thereafter said roller assembly is actuated and, by the end of one revolution, its motion must accelerate up to the tangential speed of the nearly wound olr' band, take in the new band and accelerate its motion, along with that of the spool (initially at a stop) up to the same running speed, perform the cut and apply the jointcovering strips, then again slow down and come to a stop.

It is evident that, even though high power is used and great material stresses are allowed for, such a sequence of operations cannot be performed at very high running speeds, so that it proves necessary to slow down the operating speed of the using machine and to interpose, between the jointing machine and the using machine, a compensating magazine where a considerable length of band is kept in motion zigzagging between return rollers which, at the moment the jointing is to be made, are moved together thereby enabling the further slackening of the band area on which the jointing is made with respect to the already reduced speed of the band that runs through the using machine. This compensating magazine is cumbersome and expensive and entails heavy power losses; moreover, these known systems present a drawback in that one must abruptly speed up the motion of the new spool (the mass of which may be several hundreds of kilos) by means of the traction exerted on the unwinding band, which may result in a deterioration and, at the limit, in the tearing up of the band, register inaccuracies and other troubles. In addition, it is utterly impossible to adopt a system of this kind with bands that do not exhibit a high tensile strength and tearing resistance.

The present invention is meant to solve the problem of ensuring an end to end jointing of bands in motion, possibly in rapid motion, without interrupting or slowing down said motion, without subjecting the band to abnormal stresses and without the need for bringing exceedingly high power and stress to bear on the equipment, so that said jointings may be utilized also in connection with very rapid using machines, on bands that may offer little resistance and under technically rational as well as industrially advantageous conditions. The basic principle of the invention consists first of all in accelerating the motion of the whole jointing equipment, i.e., the cutting rollers, the strip applying rollers and the new spool substituted for the preceding one, all of these kept in a condition of operating inactivity, up to the tangential speed corresponding to the running speed of the nearly wound ofl? band (this acceleration may be effected over a period of time and during a number of revolutions chosen at will); secondly, in feeding into the equipment the end of the new band, in operating the equipment through a revolution or fraction of a revolution, during which the cutting and strip-application are performed; lastly, in slowing down, for a reasonable length of time, the equipment, again brought to a condition of operating inactivity, while the using machine is already receiving the fresh band from the just started spool. This method rules out sharp accelerations or decelerations of any part of the equipment, including the new band with its spool, thereby eliminating all the inconveniences attendant on the known method, namely, speed limits, the need for a compensating magazine, and the abnormal traction of the new band.

Another principle of the invention, which proves very useful for the practical application of the method outlined, consists in this, that to ensure the required end to end jointing there is first provided a provisional jointing by superposition, which is subsequently destroyed in the equipment and replaced by the final end to end jointing.

The invention concerns, of course, both the jointing method and the machine for the practical realization of the method.

Besides exhibiting the characteristics expressly described in the application of the method according to the invention, this machine is characterized by the peculiarity of being usable to make jointing by superposition, instead of end to end, but in this case care must be taken to leave some of its parts inactive. Therefore, a machine according to the invention, installed between the spool- 3 holder and the -using machine of an operating system, acts as a universal jointing machine, whereas in the known solutions, when it comes to changing over from one type of jointing to another, it is necessary to replace the jointing machine.

The invention is further clarified in the following, with reference to an exemplifying and by no means restrictive embodiment of the same, diagrammatically illustrated in the annexed drawings, where:

FIG. 1 shows the diagram of a machine capable of performing jointings according to the method of the invention, interposed between a feeding spool-holder and the using machine, the whole exhibited under operating conditions with the spool nearly unwound and, therefore, at the moment of starting its replacement with a fresh spool;

FIGS. 2 to 7 show the same diagram of FIG. 1 in various successive phases of operation but, for the sake of clearness, the parts pertaining to the control of the operating members are omitted.

FIG. 8 shows a recommended arrangement in the preparation of the end of the band to be substituted for the wound off band.

In the drawing, the reference 1 indicates generally the first pair of feed rollers to which the jointing machine according to the invention must supply the band 2. In each particular instance the first pair of rollers may belong either to a using machine (e.g. a rotogravure printing machine or any other machine) or to a band unwinding regulator located before said using machine. This pair of rollers 1 is actuated by a motor 3 through a drive diagrammatically shown at 4.

The band 2 comes from a roll or spool 5 carried interchangeably with another similar roll 15, by a support 6 of known configuration, and is kept along a definite trajectory thanks to idle rollers 7, 8. Near the position normally occupied by the winding off spool is provided an endless belt 9 turnable around point 10, which may be made to oscillate and come into contact with the winding off spool through the action of a drive 11 (e.g. a pneumatic one). Furthermore, one of the driving wheels of the endless belt 9 may be connected, through a friction clutch 13, with the drive 4 of the using machine with a gear ratio that imparts to the endless belt 9 a speed equal (except for minor corrections destined to compensate for any slippage) to the running speed of the band 2. The fact that the motion is picked up directly from the drive 4 of the using machine or unwinding regulator 1, ensures the obtainment of an accurate speed of the endless belt 9, no matter how the speed of the machine is governed.

Around the transmission roller 8 is fitted swingable under the action of a drive 14, e.g., a pneumatic drive, an arm 19 carrying a supporting roller 16, a pressure roller 17 movable under the action of a drive, e.g., a pneumatic drive, and a blade 20, movable under the action of a drive, e.g., a pneumatic drive.

Along the trajectory of the band 2 next to the idle rollers 7, 8 are located two feed rollers '22 and 23, the first of which, normally spaced from the other, may be brought near to it, thus pressing the interposed band 2 by means of a drive, e.g. an electric drive. The two rollers 22, 23 are motionally interconnected and may be linked, through a clutch and brake assembly 25 to the drive 4 with a gear ratio that imparts to the rollers 22, 123 a tangential speed equal (except for minor corrections destined to compensate for any slippage) to the running speed of the band 2. In this case too the motion is picked up directly from the drive of the rollers 1 for the reason explained above with regard to the endless belt 5.

Along the trajectory of the band 2 after the rollers 22, 23 there are provided two cutting rollers 26, 127. The roller 26 turns about a fixed axis and carries a cutting knife 28, and the roller 27 is supported by swingable arms '29 and is normally spaced from the roller 26 to which it may be brought near by displacing the arms 29. The two cutting rollers 26, 27 are motionally connected to each other and to the rollers 22, 23 along with which they may therefore be actuated and braked by the clutch and brake assembly 25, the gear ratio being, also in this case, such as to impart to the rollers 26, 27 a tangential speed equal to the running speed of the band 2.

The roller 27 carries, in a position corresponding to that of the knife 28 on the roller 26 an insert 55 of hard metal, destined to counter the knife 28 in the cutting operation. This disposition, completed by a slightly helical fitting of the knife 28 on the roller 26, ensures a perfect cut without calling for the extremely high precision and care required in the case of the fitting of a pair of co-operating knives. The axle of the roller 27 (or another axle motionally coupled with it) carries a cam 30 which causes a scraper 31 to oscillate, bringing it near to the roller 27 when this part 5-5 passes and lifting it immediately after the passage. Beyond the cutting rollers there is mounted a scraper 32 which, under the control of electromagnets 33, 34 may be respectively approached to, or moved away from, the trajectory of the band 2. Next to said scraper 32 there is provided a pair of feed rollers 35 actuated together with the rollers 22, 23, 26, 27 at a tangential speed preferably higher than the running speed of the band 2. Beyond the feed rollers 35, there is fitted a switch 36 inserted into the circuit of the electromagnet 34 which causes the scraper 32 to move away from the trajectory of the band 2. Beyond the parts described so far, along the trajectory of the band 2, there is a pair of strip applying rollers, motionally connected to each other and to the rollers 22, 23, 26, 27, each having an area 39 laid out for receiving a strip of adhesive tape destined to form one of the joint-coverings. The roller 38 is mounted on a fixed axis, whereas the roller 37 is carried by the swingable arm 40 connected by rods 41 to the arms 29 of the cutting roller 27, so that the roller 37, normally spaced from the roller 38, may be brought near to this, its mass being balanced by that of the roller 27, so that this manoeuvre requires the minimum possible effort. The roller 38 carries coaxially a cam 42 which, by acting on two tappets 43, 44, causes an arm 45 to rise and drop, this motion occurring when the areas 39 of the rollers 37, 38 and the cutting members 28, 55 of the rollers 26, 27 on the rotation of the rollers are passing against each other. The arm 45 carries a swingable tappet 46 driven by electromagnets 47, 48, the first of which, controlled by the switch 36, puts it in active position, whilst the second, controlled by a switch 49, driven, e.g., by a cam 42, puts it in inactive position. In the active position the tappet 46 co-operates with a counter-tappet 50 connected to the arms 29, so that when the tappet 46 is in the active position, the swinging of the arm 45 produces the approach to the trajectory of the band 2 of the rollers 27, 37.

The equipment operates as follows:

During the normal operation of the using machine (FIG. 1), the endless belt 9 and the arm 19 diverge, the rollers 22, 23, 26, 27, 37, 38 are at a standstill, the clutch 25 being thrown out and under braking conditions. Also the endless belt 9 is stopped, the clutch 13 being thrown out. The pairs of rollers 22, 23, 26, 27 and 37, 38 are moved apart and the scraper 32 is lifted. Therefore, the band 2 runs freely from the spool 5 through the pair of idle rollers 7, 8 to the using machine. During the period of normal operation (which occupies most of the unwinding time of the spool 5) the machine attendants prepare for the subsequent change of spool by fitting on the support 6, in stand-by position, a fresh spool 15 by placing on the cutting roller 27 in position, next to the insert 55, one or more adhesive covering elements and by applying on the areas 39 of the rollers 37, 38 two strips of adhesive tape adapted to form jointcoverings.

The end 12a of the band 12 contained in the new spool 15 is prepared e.g. as shown in FIG. 8, i.e., it is cut tapering at 51 and provided with adhesive strips 52 on one side only, which strips seal the spool causing the end 12a of the band to adhere to the underlying layer of the band 12 that is being unwound, as well as to the adhesive strips 53 on both side (one of the adhesive surfaces of which is thus exposed) and, preferably, provided with further wider and more rearward strips 54 on both sides.

When the unwinding spool has reached a predetermined degree of depletion, the change of spool is prepared for. To this end, the spools 5 and are interchanged, causing their support to rotate in a known manner and, by means of the drive 11, the endless belt 9 is brought into contact with the spool 15 still at a stop, while, by means of the drive 14, the arm 19 with its supporting roller 16 is brought into contact with the band 29 that continues to unwind from the spool 5.

Furthermore, the clutch is shifted frombraking position to engagement position, so that the motion of the rollers 22, 23, 26, 27, 38, is gradually accelerated (these rollers remaining, however, inoperative because the respective pairs are moved away) till the working speed is arrived at, when the tangential speeds of all the rollers are substantially equal to the running speed of the band 2 (FIG. 2).

Through the engagement of the clutch 13, the motion of the endless belt 9 (as well as that of the spool 15, which is coupled with it by contact friction) is gradually accelerated to the Working speed, when the tangential speed of the spool 15 is equal to the running speed of the band 2.

Moreover, by means of the drive 24, the feed roller 22 is brought near the roller 23, engaging this pair of rollers with the band 2 that runs in between and, through the feeding of current to the electromagnet 33, the scraper 32 is displaced with its edge in contact with the band 2 (FIG. 3).

From the moment the rollers 22 and 38 have been started, the cam 42 is causing the arm 45 to swing periodically, but the tappet 46 in the oft position does not impart any motion to the counter-tappet 50: furthermore, the scraper 31, driven by the cam 30 moves periodically toward and away from the surface of the roller 27: the moving away period corresponds to the passage under the scraper 31 of the adhesive covering elements applied next to the insert as explained above, so that these elements are not removed by the scraper 31. The equipment is now ready to perform, on command, the jointing and the replacement of the old band 2 with the fresh one 12.

As the chosen moment, the drive 18 causes the displacement of the pressure roller 17, which pushes the band 2 into contact with the surface (running at the same linear speed) of the new spool 15. On the passage of the adhesive strips 53 and, subsequently, of the strips 54, these get stuck on the surface of the band 2, tear away the strips 52 and carry the end of the band 12 solidly with the band 2 between the idle rollers 7, 8, then between the feed rollers 22, 23. From this moment onward, also the band 12 is positively fed, and the function of the strips 53, 54 is over. On pursuing its advancement, the end of the band 12 encounters the scraper 32 lowered: this overcomes the adhesion of the strip 53 and deflects the end of the band 12, sending it between the feed rollers 35, which exert on the band 12 a traction strong enough to overcome also the adhesion of the strips 54, whereafter the jointing by superposition, which had been temporarily ensured by the strips 53, 54 between the two bands 2, 12 is undone, and the two bands run together in the equipment without mutual jointing. In its forward path, the end of the band 12 draws near until it touches the switch 36 (FIG. 4). Following the turning off of the switch 36 by the end of the band 12, the electromagnets 34 (which return to rest the scraper 32) and 47 (which brings to on position the tappet 46) are energized. Therefore when, in the rotation of the roller assembly 22, 38 the cam 42 causes the arm 45 to swing, this, through the tappet 46, which is now on, transmits the motion to the arms 29, and through the connecting rods 41, to the arms 40, causing the mutual approach of the pairs of rollers 27, 28 and 37, 38 respectively. Consequently, when the knife 28 carried by the roller 26 passes against the area 55 of the roller 27 said knife cuts simultaneously the bands 12 and 2 interposed between said two rollers (FIG. 5). Thanks to the slightly helical disposition of the knife 28, this action is performed gradually and regularly.

The band 2 proceeds then under the traction of the rollers 1 and 37, 38 together, while the new band 12 advances at the same speed, pushed by the rollers 22, 23 and 26, 27, the two edges of the cut produced correspondingly on the two bands by the knife 28 being juxtaposed. Meanwhile the feed rollers 35 continuing their rotation expel the end 12a cut from the band 12 while the tail end 2a cut from the band 2 has been caught by the adhesive covering elements of the roller 27 and carried downwards where the scraper 31 has detached it from the roller 27 and conveyed it towards the floor. At the same time, either automatically or following a command, by means of the actuating member there has been lifted the knife 20 which cuts the band 2 near the wound off spool 5. In their advance, the edges of the cut that still separates the bands 2, 12 arrive juxtaposed between the rollers 37, 38 which apply the joint covering strips 39 thereby completing the end to end jointing (FIG. 6). In this lapse of time, the switch 49 driven e.g. by the cam 42 has activated the electromagnet 48 which, however, has not been able to bring to off" position the tappet 46, which is still retained by its engagement with the counter tappet 50.

When in its rotation the cam 42. causes the arm 45 to be again lowered, also the arms 29 and 40 are lowered once more moving away the pairs of rollers 26, 27 and 37, 38, and the tappet 46 returns to off position, thus precluding a further activation of the knife 28. The tail end 2a of the band 2 has in the meantime been completely ejected, the rollers 22, 23 may again be moved away either automatically or by means of a command, the arm 19 and the endless belt 9 are returned to rest, the clutch 13 is disengaged allowing the endless belt 9 to stop and the clutch 25 is disengaged and put in braking conditions for stopping in a reasonable length of time, the rollers 22 to 38 which, owing to their great inertia, would continue rotating for a long while. Hereupon (FIG. 7) the using machine continues its normal operation, now fed by the new band 12 coming from the new spool 15 and the old depleted spool 5 is removed, whereafter the equipment may again be set up as explained at the beginning, for the next change of spool.

It appears from the above that the operations car ried out by the equipment according to the invention and making up the method that is the object of the invention, in view of their gradual and progressive nature are not such as to involve restrictions on the band running speed, so that no slowing down is required for the Working of the using machine when the joint is being made, nor will the band 12 be overloaded when entering.

It is also clear that the machine, adapted, while in full operation, to make end to end joints with joint coverings, may make jointing by superposition, when, however, one should see to it, that the rollers 22 to 38 and the knife 20 are kept inoperative (and, therefore, also stationary, the clutch 25 being disengaged). In this case the jointing by superposition, normally made as an intermediate step then destroyed, is not undone but left as final.

It is evident that several modifications may be introduced in the descriptions given by way of exemplification, especially with regard to the disposition of the parts, the nature and mode of operation of the control members, the addition of such automatic and safety devices as are not described hereinasmuch as they are not essential to the understanding of the principle of the invention, and to the substitution of technical equivalents in general.

A temporary jointing by superposition destined to be subsequently destroyed is an extremely expedient method for introducing in due course into the equipment the end of the new band, but it must be understood that also other means may be used for this purpose, especially in cases where it is not interesting to use the machine according to the invention also for final jointing by superposition.

As a variant, it may be provided that the inactive condition of the pair of cutting rollers be possibly realized, instead of by moving the two rollers away from each other, by retracting the knife into one of the rollers and displacing it until it protrudes from the roller surface, only for the time it is in action.

The various successive handlings or manoeuvres required for implementing in the correct sequence the various phases of the method may advantageously be performed by means of a successive multiple position control member, preferably with the adoption of such control and assent devices as prevent the starting of each phase till the preceding phase has been correctly completed.

Having thus described my invention, what I claim is:

1. A machine for forming an end-to-end joint provided with joint-covering strips on bands moving from feed spools to a user machine, particularly for replacing a first band coming from an old feed spool which is being depleted, with a second band coming from a new feed spool, comprising a source of power, an accelerating member, means for connecting said accelerating member to said source of power, means for operatively connecting said accelerating member to said new feed spool to accelerate said new feed spool before said second band is fed from said new feed spool, a pair of feed rollers, said bands passing between said feed rollers, means for connecting said feed rollers to said source of power, means for bringing said feed rollers from an inoperative condition to operating conditions wherein said feed rollers engage interposed bands, means for pressing said first hand against the rotating new feed spool before said second band has been fed from said new spool thereby to create a temporary superposition joint between the first band and the free end of the second band and to initiate feeding of the second band, a pair of cutting rollers, said superposed bands passing between said cutting rollers, means for connecting said cutting rollers to said source of power, means for bringing said cutting rollers through at most one revolution from an inoperative condition to operating conditions wherein said cutting rollers out said interposed bands, a pair of strip-applying rollers, said bands passing between said strip-applying rollers, means for connecting said stripapplying rollers to said source of power, means for bringing said strip-applying rollers from an inoperative condition to operating conditions wherein said strip-applying rollers apply strips on said interposed bands, and control means for operatively connecting said accelerating member to said source of power and to said new feed spool, for connecting said feed, cutting and strip-applying rollers to said source of power, for bringing said feed, cutting and strip-applying rollers into operating conditions, and after at most one revolution of said cutting rollers, for bringing said cutting rollers again in inoperative condition, for bringing said feed and strip-applying rollers again in inoperative condition, for disconnecting said accelerating member from said new spool, and for disconnecting said accelerating member, feed, cutting and stripapplying rollers from said source of power.

2. A machine as set forth in claim 1, further comprising means for deflecting and ejecting the tail end of said first band and the head end of said second band, and means for cutting the tail end of said first band near said old feed spool.

3. A machine as set forth in claim 6, wherein said source of power comprises a mechanical drive connected to said user machine, said means for connecting the accelerating member to said source of power comprise a friction clutch device, and said means for connecting said cutting and strip-applying rollers to said source of power comprise a friction clutch device of the type acting alternatively as a brake.

4. A machine as set forth in claim 6, wherein said accelerating member comprises an endless belt, a fixed support member for said endless belt, and a movable support member for said endless belt, said means for operatively connecting the accelerating member to said new spool being connected to said movable support member.

5. A machine as set forth in claim 6, further comprising a first arm, a second arm operatively connected to said first arm, one of said cutting rollers being pivoted on said first arm, one of said strip-applying rollers being pivoted on said second arm, a cam solid in rotation with one of said rollers, a lever moved by said cam, and a tappet interposed between said lever and one of said arms, said tappet having an inoperative position and an operating position wherein it operatively connects said lever and said arm.

6. A machine as set forth in claim 1, wherein one of said cutting rollers has an helical protruding knife, and the other cutting roller has a corresponding insert of hard metal capable of cooperating with said knife in the cutting of the bands.

7. A machine as set forth in claim -1, further comprising a pair of pull rollers located between the pair of cutting rollers and the pair of strip-applying rollers, a scraper located between said cutting rollers and said pair of pull rollers for deflecting the head end of the band coming from said new spool, said head end passing between said pull rollers, and a switch device cooperating with said head end of the band for controlling the means for bringing said cutting and strip-applying rollers in operative condition.

8. A machine as claimed in claim 1, said pressing means comprising a pivotally mounted arm carrying a pressure roller thereon that bears against said first band to press said first hand against the rotating new feed spool.

References Cited UNITED STATES PATENTS 2,745,464 5/1956 Auerbacher et al 242-584 ROBERT F. STAHL, Primary Examiner U.S. Cl. X.R. 156-157 

